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I came across this story on WIRED.com's website. It's a good illustration of what happens when prices (in this case, energy prices) rise.

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In a world where sun-powered garden lights seem like a nifty idea, new technologies touted by solar energy startups sound very far out.

Entrepreneurs promise that soon solar-energized "power plastic" will radically extend the battery life of laptops and cell phones. Ultra-cheap printed solar cells will enable construction of huge power-generating facilities at a fraction of today's costs. And technologies to integrate solar power-generation capability into building materials will herald a new era of energy-efficient construction.

Those are ambitious goals for a technology famous for powering pocket calculators, but investors are paying heed. This year, solar startups have snapped up more than $100 million in venture capital to develop printable materials capable of converting sunlight into electrical power. Soaring energy demand, as well as short supplies of polysilicon, a key ingredient in most solar cells, is fueling interest in alternative materials.

"These technologies look incredibly more real than they did five years ago," said Dan Kammen, founding director of the Renewable and Appropriate Energy Laboratory at the University of California at Berkeley. Kammen predicts solar sources, which today produce less than 1 percent of power consumed nationwide, could eventually meet one-fifth of U.S. energy demand.

Printed solar cells, produced with conductive metals and organic polymers in place of silicon, could help. As early as next year, startups plan to begin manufacturing printed solar products for use in power-generating facilities, rooftop installations and portable gadgets. While industry experts don't expect manufacturing on a massive scale to be viable for years, production capability is ramping up quickly.

Executives at Nanosolar, based in Palo Alto, California, plan to finish building a factory next year to churn out thin-film solar cells using copper-based semiconductors instead of silicon.

"Silicon models are too expensive in the first place," said Martin Roscheisen, Nanosolar's CEO, who expects the company will be able to build a 400-megawatt plant for about $100 million. Providing equivalent capacity using silicon technology, Roscheisen estimated, would cost close to $1 billion.

When Nanosolar's products become commercially available, Roscheisen plans to warranty the cells for 25 years -- similar to silicon solar products.

Miasolé, in neighboring Santa Clara, California, has developed a competing thin-film photovoltaic cell using a layer of photoactive material containing a compound called CIGS. The company plans to incorporate the technology into building materials and rooftop solar installations.

On the shorter end of the power-generation life cycle, Konarka, a startup in Lowell, Massachusetts, has agreements in place with manufacturers to produce a printed "power plastic" to supply solar energy for portable devices.

"When people think of solar, they think of rooftop, grid-connected. We're trying to change that mindset," said Daniel Patrick McGahn, Konarka's chief marketing officer. Unlike silicon-based solar cells used on rooftops today, Konarka's specialized plastics typically last years, but not decades. The company is marketing its technology for use in products with similar life spans.

While research into printed photovoltaic technologies dates back decades, progress on non-silicon applications has accelerated in recent years due to the shortage of polysilicon, said Travis Bradford, president of the Prometheus Institute for Sustainable Development in Cambridge, Massachusetts. Today, nearly 95 percent of solar cells use semiconductor-grade silicon, he estimates, but that should drop to around 80 percent over the next few years.

To compete against silicon solar manufacturers, Bradford says developers of new technologies will need to show that they can be cost-effective. They'll also have to prove supplies of core materials are adequate for mass production and demonstrate that their products don't degrade too quickly. While he's optimistic about the prospects, he's not convinced any technology is meeting all the criteria today.

"It takes a lot longer and a lot more money to commercialize technology than people think ... which is why crystalline silicon has been around for so long," he said.

Still, printed photovoltaics could soon be ready for commercial use, said Raghu Das, CEO of research firm IDTechEx. The key hurdle remaining is to make materials resilient enough to last for years. Das expects manufacturers to resolve those concerns and produce viable printed photovoltaics in 2009 or 2010. He envisions large-scale deployment around 2012.

In the meantime, solar startups entice investors with visions of clean, low-cost, energy-generating capability bundled into a range of products, from building materials to cell phones. While that vision may eventually prove realistic, says Das, it's still quite futuristic.

"As plastics are used to make this and not silicon, it will be incredibly low-cost -- you could compare it to the cost of printing ink on paper," he said. "However, if it was ready today, everybody would be doing it."